Threat Model and Defense Scheme for Side-Channel Attacks in Client-Side Deduplication  

作　　者：Guanxiong Ha Hang Chen Chunfu Jia Mingyue Li 

机构地区：[1]College of Cyber Science,Nankai University,Tianjin 300350,China [2]Tianjin Key Laboratory of Network and Data Security Technology,Tianjin 300350,China

出　　处：《Tsinghua Science and Technology》2023年第1期1-12,共12页清华大学学报（自然科学版（英文版）

基　　金：supported by the National Key R&D Program of China (No.2018YFA0704703);National Natural Science Foundation of China (Nos.61972215,61972073,and 62172238);Natural Science Foundation of Tianjin (No.20JCZDJC00640).

摘　　要：In cloud storage,client-side deduplication is widely used to reduce storage and communication costs.In client-side deduplication,if the cloud server detects that the user’s outsourced data have been stored,then clients will not need to reupload the data.However,the information on whether data need to be uploaded can be used as a side-channel,which can consequently be exploited by adversaries to compromise data privacy.In this paper,we propose a new threat model against side-channel attacks.Different from existing schemes,the adversary could learn the approximate ratio of stored chunks to unstored chunks in outsourced files,and this ratio will affect the probability that the adversary compromises the data privacy through side-channel attacks.Under this threat model,we design two defense schemes to minimize privacy leakage,both of which design interaction protocols between clients and the server during deduplication checks to reduce the probability that the adversary compromises data privacy.We analyze the security of our schemes,and evaluate their performances based on a real-world dataset.Compared with existing schemes,our schemes can better mitigate data privacy leakage and have a slightly lower communication cost.

关 键 词：cloud storage DEDUPLICATION side-channel PRIVACY 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]